I've actually read up on this picture, and it isn't at all what it seems.
While it looks like the bat is being tickled, it isn't. It is being crushed. This picture was taken during the last millisecond of it's life, right at the moment where it realized it would die, and a millisecond later, all of its ribs were broken and forced into its internal organs, causing massive (if you can say that for such a small creature) amounts of internal bleeding, and lead to a slow, terrible death.
The expression on the bat's face is not one of joy, it is one of terror, pain, and utter confusion.
And I'm completely ************ you this is probably just a picture of a bat being tickled.